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  • K Offline
    K Offline
    kashry
    wrote on last edited by kashry
    #1

    Hello

    I am new to Qt and am fairly new to programming (so apologies if I have a lack of understanding), I have a project I am doing but I am stuck and do not know how to go about it. The project is to have 2 windows open on a raspberry pi, one window ("send window") is to be drawn on (like a whiteboard) and the other window ("receive window") copies and displays the exact same drawing. My problem lies in that I need the communication between the windows to be physical (connect some of the pins together and whatnot) and so I assume the information must travel via UART. I have managed to code the "send window" to be a whiteboard, but I am stuck on how to transfer the drawing to the "receive window". I figured I could probably convert the "send window" image to a pixmap and then send that after converting it but that sounds like it would take forever and I do not want much lag between me drawing on the "send window" and the drawing being displayed (in real time) on the "receive window".

    Any help would be appreciated and I thank you in advance :)

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    • eyllanescE Offline
      eyllanescE Offline
      eyllanesc
      wrote on last edited by
      #2

      @kashry I don't think UART has enough bandwidth to send images, and even if it did, it is not optimal to do so. Instead of sending the image you should send the instructions, for example if a rectangle is drawn on the interface then send the position and dimension of the rectangle, and with that information you draw the rectangle on the other side

      If you want me to help you develop some work then you can write to my email: e.yllanescucho@gmal.com.

      K 1 Reply Last reply
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      • eyllanescE eyllanesc

        @kashry I don't think UART has enough bandwidth to send images, and even if it did, it is not optimal to do so. Instead of sending the image you should send the instructions, for example if a rectangle is drawn on the interface then send the position and dimension of the rectangle, and with that information you draw the rectangle on the other side

        K Offline
        K Offline
        kashry
        wrote on last edited by
        #3

        @eyllanesc thanks for getting back to me, the problem is that it isn't simple shapes being drawn on the interface, it is a drawing (like a smiley face) done by hand (or rather by mouse haha). But going with the idea of instructions, are there any instructions to colour a pixel on the "receive" interface as it is being coloured in on the "send" interface?

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        • SGaistS Offline
          SGaistS Offline
          SGaist
          Lifetime Qt Champion
          wrote on last edited by
          #4

          Hi,

          Aren't you describing a mirroring mode ?

          From your description you have the same stuff that must be shown on two different screens attached to the same device.

          Interested in AI ? www.idiap.ch
          Please read the Qt Code of Conduct - https://forum.qt.io/topic/113070/qt-code-of-conduct

          K 1 Reply Last reply
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          • SGaistS SGaist

            Hi,

            Aren't you describing a mirroring mode ?

            From your description you have the same stuff that must be shown on two different screens attached to the same device.

            K Offline
            K Offline
            kashry
            wrote on last edited by
            #5

            @SGaist hey, yeah I guess I am but with no inversions. An exact replica on 2 different screens.

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            • fcarneyF Offline
              fcarneyF Offline
              fcarney
              wrote on last edited by
              #6

              Does it update in real time? If it does then what events happen on one should be sent to the other. Like @eyllanesc said, those would be the "instructions" of what to draw.

              C++ is a perfectly valid school of magic.

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              • J Offline
                J Offline
                jimsmiths
                Banned
                wrote on last edited by
                #7
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